Despite the loss of his dear friend, the Seventh Hokage can still use the Sage Mode. Fans were delighted to see that Naruto still retained some of his powers and that he is capable of taking down strong opponents. However, he had to use Shadow Clones in order to collect the natural energy.
Without Kurama, he has the ability to develop his skills even further. With Sage Mode, he gets access to all his five chakras. And he can learn infinite jutsu.
Essentially, this means that Naruto has an eternity to train and get stronger. In this eternity, Naruto can easily devise ways to take his powers to the next level. He can improve upon his Sage Mode and develop new forms of it, or he can develop new forms of jutsu that would be unique to him.
Baryon Mode is a strength only accessible to Kurama and his Jinchuriki, where the chakra of both fuse together, similar to nuclear fusion, and give rise to new energy. However, the price to pay for this insanely powerful form is Kurama's death, which he hid from Naruto.
Kurama ended up burning away and, as such, there is no body left for him behind as he was a mass of chakra, to begin with. Thus, he cannot be resurrected using techniques such as Edo Tensei.
Kishimoto has always told us that Sasuke and Naruto will always be equals. Now, Sasuke has lost his rinnegan, Naruto has lost Kurama. If Sasuke ends up getting rinnegan back, then, yes, Kurama will come back, or vice versa.
Without Kurama, Naruto lost a big part of what defined his strength, and what also made him who he really is.
To the fandom it seems that, although it would be extremely difficult, it is not impossible, and at worst the fight might result in a draw. The reason for that is, even without Kurama, Naruto still retains his Sage of Six Paths mode and his own Sage Mode that he mastered through training.
To sum things up, there is a sliver of a chance that Kurama comes back, and that could be due to a plothole, which isn't uncommon in the Naruto series. However, it is quite unlikely that Kurama will return to the series and another jinchuriki will not be introduced in the series.
Although Naruto usually uses the Six Paths' Sage Mode along with the Kurama Chakra Mode, there is no reason he cannot use it without Kurama's strength. In fact, Naruto can still use the basic Sage Mode, which is enough for him to take down a roster of enemies.
In Boruto, Naruto Uzumaki gained a new transformation that allowed him to channel the maximum output of a new power, called Baryon Mode. This form was created by using Naruto and Kurama's chakra as raw materials to give birth to a completely new and stronger chakra, just like nuclear fusion.
Baryon Mode is one of Naruto's most powerful forms, allowing him to tap into Kurama's full power and use it to defeat his enemies.
The only two ways Naruto can get the rinnegan is through blood transfusion from Sasuke or absorb enough of Sasuke chakra and merge with his chakra.
Although Naruto lost Kurama, his Six Paths Powers should still be accessible to him. In Naruto's fight against Madara, he displayed the ability to use Six Paths Sage Mode without tapping into the power of the chakra cloak.
Naruto DOES still have Six Paths amps after his fight with Sasuke. You could NEVER prove he doesn't afterwards.
If Boruto manages to learn how to control the different chakras inside of him, he might become the next jinchuriki – as he is an Uzumaki too. Though not much is known about the Karma mark other than the threats it has caused. But it can also be used to bring back Kurama.
Sadly, there's no hint of Kurama coming back to life in the Boruto manga series when writing this post. So, it's safe to say that's how things will stay in the anime as well. In the manga, Kurama died in chapter 55, and episode 219 adapted 11 pages from the same chapter.
No, he ain't comming back. His chakra (his existence as he is made of it) was consumed and literally faded away which he himself stated.
1 Kaguya Otsutsuki
As the Ten-Tails jinchuriki, Kaguya had an incredible amount of chakra, far superior to any character in Naruto. This allowed Kaguya to easily use her kekkei mora techniques. She is the only character in the series who was able to create a Truth-Seeking Ball, so huge that it could destroy the earth.
No, he isn't. He is still capable of using his strongest mode which was granted by Hagoromo.
When Kurama died, Naruto got a massive nerf-down. He got 200 times weaker.
However, after gaining better powers, such as Kurama Chakra Mode and even Six Paths Sage Mode, Naruto relied on Sage Mode quite rarely. As such, he didn't get to properly improve his usage of this power. After losing Kurama, Naruto needs to train in the Sage Mode arts once again and by doing so, improve its usage.
No, Naruto will not become a jinchuriki in the Boruto anime, as he would not want to replace Kurama just to get stronger. While he was the strongest living character in the verse, losing Kurama was a huge blow to him as well as the Hidden Leaf Village.
In Boruto, Kurama did die, but he can be revived because Naruto has his chakra mixed with the Kyuubi after spending so many years without any seal. Reviving Kurama is only possible because Naruto's got power of six paths light which gives him the power to revive beings, organs, known as Yin Yang Release.